Efeito da fotobiomodulação associada ao uso de carvão ativado no reparo ósseo em tíbia de ratos - aspectos morfológicos, bioquímicos e biomecânicos

Abstract

In the period between 2012 and 2014 the Unified Health System has invested more than R$ 370 million in musculoskeletal surgical procedures in Brazil, among several factors, bone loss and healing problems after fractures are largely responsible for such surgeries. It is known that phototherapy contributes to optimize the repair process. The use of biomaterials that help bone repair process has become part of clinical practice and the subject of several studies. The objective of this study was to verify the use of activated carbon and the interaction of this with phototherapy on the bone repair process in experimental model, evaluating histological, biochemical, molecular, and biomechanical changes. Materials and Methods: 40 male Wistar rats was used, weighing between 150g to 200g. After anesthesia with ketamine hydrochloride association and Xylazine (90mg / kg and 10mg / kg, IP), the animals was submitted to the bone defect process made in the monocortical region of both tibias. Immediately after surgery, the rats was randomized into six groups: control (CTL), untreated bone defect (NT), bone defect treated with activated carbon (AC), bone defect treated with laser (L6J), bone defect treated with actived carbon and laser 830nm, 6J - 100mW (AC + L). After 28 days blood was collected and the animals was euthanized for complete removal of the tibia and subsequent histological, biochemical molecular, and biomechanical analyses. Results: Step 1: in this phase, porosity and surface characteristics of 4 different coals were evaluated. Activates Carbon 1 of commercial origin and Activates Carbon 4 produced in the laboratory presented more suitable characteristics for use in bone repair and of these, the activates carbon 4 was selected for continuity of the study. Subsequently, in step 2 a pilot protocol evaluated the morphological aspects of different irradiation parameters of phototherapy in animals. Five groups treated with 1, 3, 6 and 10 J (830nm; 100mW) were evaluated. The animals treated with 6J (214.28 J / cm2) presented better quality of the repair process and this energy was selected for the final protocol. In step 3 of the study, the results showed that AC group promoted increased strength and reduction of deformation, these data were found also in groups treated with Laser (L) and in association with Activated Carbon (AC+L). It

was observed a reduction of Alkaline Phosphatase on groups treated with Activated Carbon (AC) and Laser (L). In conclusion, the use of Activated Carbon and photobiomodulation promoted improvement of repair process however, these data were not observed on the association of both resources.